Sitecore PowerShell Extensions Script for finding pages where a rendering is used

wheresmyrendering.ps1

# 1) Path to Presentation node of your Site
$presentationPath = "/sitecore/content/TennantGroup/Tennant/Shared Website/Presentation"
# 2) IDs for derived Metadata Partial Design template
$metadataPartialDesignTemplateId = "{C546A218-0707-4B3E-905B-EBD866533AE7}"
# 3) ID for derived Partial Design template
$partialDesignTemplateId = "{341CDBE1-FE54-47F5-AAB9-016AC4FA8C0D}"
# 4) ID for derived Page Design template
$pageDesignTemplateId = "{39543BFF-CE95-40D3-9873-E5E5A0E1BDFF}"
# 5) Path for Home page
$homePagePath = "/sitecore/content/TennantGroup/Tennant/Developer Website/Home"

$renderingId = Show-Input "Enter the ID of a rendering:"
$rendering = Get-Item -Path master: -ID $renderingId

$partialDesignsPath = $presentationPath + "/Partial Designs"
$pageDesignsPath = $presentationPath + "/Page Designs"

$sxaPartialDesignTemplateId = "{BF680756-B2FA-4CAE-8B69-EE361080616F}"
$sxaMetadataPartialDesignTemplateId = "{C2A8E276-1757-4957-9DD5-8669B79FD80D}"
$partialDesignsQuery = $partialDesignsPath + "//*[@@templateid='" + $metadataPartialDesignTemplateId + "' or @@templateid='" + $partialDesignTemplateId + "' or @@templateid='" + $sxaPartialDesignTemplateId + "' or @@templateid='" + $sxaMetadataPartialDesignTemplateId + "']"
$partialDesigns = Get-Item -Path master: -Query $partialDesignsQuery

$sxaPageDesignTemplateId = "{EBCFFAE1-B6B4-4B50-B722-155E869FC430}"
$pageDesignsQuery = $pageDesignsPath + "//*[@@templateid='" + $pageDesignTemplateId + "' or @@templateid='" + $sxaPageDesignTemplateId + "']"
$pageDesignsItem = Get-Item -Path master: -Query $pageDesignsPath
$pageDesignsCollection = Get-Item -Path master: -Query $pageDesignsQuery
$sxaTemplatesMappingFieldId = '{BA1F60D6-3DEB-40CC-BB61-EEC772279EE1}'
$decoded = [System.Web.HttpUtility]::UrlDecode([System.Web.HttpUtility]::UrlDecode($pageDesignsItem[$sxaTemplatesMappingFieldId]))
$pageDesignLookup = [System.Web.HttpUtility]::ParseQueryString($decoded)

$referrerPages = @()

foreach ($partialDesign in $partialDesigns) {
    #Write-Host $partialDesign.Name
    if (($partialDesign["__Renderings"] -match $rendering.ID.ToString()) -or ($partialDesign["__Final Renderings"] -match $rendering.ID.ToString())) {
        $message = "Found rendering " + $rendering.Name + " within partial design " + $partialDesign.Name
        #Write-Host $message
        $pageDesigns = Get-ItemReferrer -Item $partialDesign | Where-Object { $_.TemplateId -eq $pageDesignTemplateId }
        #Write-Host " " + $pageDesigns.Name
        $itemPaths = @()
        $pageDesignIds = @()
        $pageDesignNames = @()
        foreach ($pageDesign in $pageDesigns) {
            $innerMessage = "  Partial design " + $partialDesign.Name + " referenced by page design " + $pageDesign.Name
            #Write-Host $innerMessage
            $pageDesignIds += $pageDesign.ID
            $pageDesignNames += $pageDesign.Name
            $query = $homePagePath + "//*[@#Page Design#='" + $pageDesign.ID + "']"
            $page = Get-Item -Path master: -Query $query | Select -First 1
            
            if ($page -eq $null) {
                #Write-Host "  null item encountered"
                #Write-Host $pageDesignLookup.AllKeys
                foreach ($key in $pageDesignLookup.AllKeys) {
                    #Write-Host $key
                    if ($pageDesignLookup[$key] -eq $pageDesign.ID.ToString()) {
                        $pageTemplate = Get-Item -Path master: -ID $key
                        $pages = Get-ItemReferrer -Item $pageTemplate | Where-Object { $_.Paths.IsContentItem -and $_.TemplateId -eq $pageTemplate.ID }
                        #Write-Host $pages.Length
                        #Write-Host $pages[0].Paths.FullPath
                        #Write-Host $pages[1].Paths.FullPath
                    }
                }
            }
            
            $resultObject = [PSCustomObject]@{
                RenderingID = $rendering.ID
                RenderingName = $rendering.Name
                PartialDesignID = $partialDesign.ID
                PartialDesignName = $partialDesign.Name
                PageDesignID = $pageDesign.ID
                PageDesignName = $pageDesign.Name
                ItemPath = $page.Paths.FullPath
            }
            $referrerPages += $resultObject
        }
    }   
}

$dialogTitle = "Pages using the '" + $rendering.Name + "' rendering."
$referrerPages | Show-ListView -InfoTitle $dialogTitle

This script can be copied and pasted into a new script window in the PowerShell ISE interface in Sitecore.