Below code pulls all Import and Query activities from Automation Studio along with the names of target Data Extensions which get updated by those activities. See prerequisites in comments.

de-inventory-with-data-sources.html

<!--–– Copyright © 2020 Zuzanna Jarczynska http://sfmarketing.cloud ––-->

<script runat="server">
Platform.Load("Core", "1");

var authEndpoint = 'https://mcxxxxxxxxxxxxxx.auth.marketingcloudapis.com/', //provide API endpoint
    client_id = 'xxxxxxxxxxx', //pass Client ID
    client_secret = 'xxxxxxxxxx'; //pass Client Secret

var targetDE = 'xxxx-xxxx-xxxx-xxxx-xxxxx'; //pass external key of the target DE  

//initiate WSProxy
var prox = new Script.Util.WSProxy();

//initiate and clear data extension
var logDE = DataExtension.Init(targetDE);
var props = {
    CustomerKey: targetDE
};

try {
    var data = prox.performItem("DataExtension", props, "ClearData");
} catch (error) {
    Write(Stringify(error));
}

//authenticate to get access token
var payload = {
    client_id: client_id,
    client_secret: client_secret,
    grant_type: 'client_credentials'
};
var url = authEndpoint + '/v2/token';
var contentType = 'application/json';

var accessTokenRequest = HTTP.Post(url, contentType, Stringify(payload));

if (accessTokenRequest.StatusCode == 200) {
    var tokenResponse = Platform.Function.ParseJSON(accessTokenRequest.Response[0]);
    var accessToken = tokenResponse.access_token;
    var rest_instance_url = tokenResponse.rest_instance_url;
}

var headerNames = ["Authorization"];
var headerValues = ["Bearer " + accessToken];

//api call to get all imports  
function getAllImports(accessToken, headerNames, headerValues) {
    var pagesFetched = 0;
    var pagesCount = 1;
    do {
        try {
            var page = pagesFetched + 1;
            var importsUrl = rest_instance_url + 'automation/v1/imports?$page=' + page;
            var getImports = HTTP.Get(importsUrl, headerNames, headerValues);

            if (Platform.Function.ParseJSON(getImports.Status) == 0) {
                var importContent = Platform.Function.ParseJSON(String(getImports.Content));
                for (var i = 0; i < importContent.items.length; ++i) {
                    var importName = importContent.items[i].name,
                        importDestinationObjectTypeId = importContent.items[i].destinationObjectTypeId,
                        importDestinationObjectId = importContent.items[i].destinationObjectId;

                    if (importDestinationObjectTypeId == 310) {
                        var cols = ["Name", "CustomerKey", "ObjectID"];
                        var filter = {
                            Property: "ObjectID",
                            SimpleOperator: "equals",
                            Value: importDestinationObjectId
                        };
                        var data = prox.retrieve("DataExtension", cols, filter);
                        if (data.Results[0].Name) {
                            logDE.Rows.Add({
                                DEName: data.Results[0].Name,
                                DEKey: data.Results[0].CustomerKey,
                                ImportName: importName
                            });
                        }

                    }
                }
            } else {
                Write("Error");
            }
            pagesFetched++;
        } catch (error) {
            Write("Exception Error: " + Stringify(error));
            pagesFetched = pagesCount + 1;
        }
    } while (pagesFetched < pagesCount);
}

//api call to get all queries 
function getAllQueries(accessToken, headerNames, headerValues) {
    var pagesFetched = 0;
    var pagesCount = 1;
    do {
        try {
            var page = pagesFetched + 1;
            var queriesUrl = rest_instance_url + 'automation/v1/queries?$page=' + page;
            var getQueries = HTTP.Get(queriesUrl, headerNames, headerValues);

            if (Platform.Function.ParseJSON(getQueries.Status) == 0) {
                var queryContent = Platform.Function.ParseJSON(String(getQueries.Content));
                for (var i = 0; i < queryContent.items.length; ++i) {
                    var queryName = queryContent.items[i].name,
                        targetKey = queryContent.items[i].targetKey,
                        targetName = queryContent.items[i].targetName;
                    logDE.Rows.Add({
                        DEName: targetName,
                        DEKey: targetKey,
                        QueryName: queryName
                    });
                }
            } else {
                Write("Error");
            }
            pagesFetched++;
        } catch (error) {
            Write("Exception Error: " + Stringify(error));
            pagesFetched = pagesCount + 1;
        }
    } while (pagesFetched < pagesCount);
}

if (accessToken != null) {
    getAllImports(accessToken, headerNames, headerValues);
    getAllQueries(accessToken, headerNames, headerValues);
}
</script>

As a prerequisite, create a Data Extension to store results of the script. The Data Extension needs to have the following structure:

Field: DEName / Text / 250
Field: DEKey / Text / 250
Field: ImportName / Text / 250
Field: QueryName / Text / 250

Note, that above script will only return the names of Data Extensions updated by the two types of Automation Studio activities. To pull a full list of all Data Extensions in the account, see here: https://gortonington.com/data-extension-inventory-for-your-sfmc-business-unit/

Hi Zuzanna,
Thanks for this solution, this helped me in solve one of my use case. I have a query, Instead of storing the data which we are looking for in a data extension by adding external key, Is it possible to build a custom solution using cloud page to fetch list of SQL query Activities which uses my data extension in Select statements. Something like https://cloud.e.abc.com/Traget_DE?DEName=ABC by adding my target DE name in cloud page should return result.
Thanks in advance.