AutoCompleteTextView implemented in Jetpack Compose.

ComposeAutoCompleteTextField.kt

@Composable
fun AutoCompleteTextField(
    initialText: String,
    itemList: List<String>,
    onQuery: (String) -> Unit,
    onClearResults: () -> Unit,
    modifier: Modifier = Modifier
) {
    val (field, changeField) = savedInstanceState(saver = TextFieldValue.Saver) { TextFieldValue(text = initialText) }
    LaunchedEffect(subject = field.text) {
        if (!field.isBlank()) {
            delay(1000L)
            onQuery(field.text.trim())
        }
    }
    LazyColumn(modifier = modifier.animateContentSize()) {
        item { 
            TextField(
                value = field,
                onValueChange = {
                    changeField(it)
                    onClearResults()
                },
                maxLines = 1
            ) 
        }
        if (itemList.isNotEmpty() && !field.isBlank()) {
            items(itemList) { item ->
                Text(
                    item,
                    modifier = Modifier
                        .padding(4.dp)
                        .clickable(onClick = {
                            changeField(TextFieldValue(item))
                        })
                )
            }
        }
    }
}

fun TextFieldValue.isBlank() = this.text.isBlank()

Compose version: 1.0.0-alpha07
Assuming that on querying the backend, earlier result list will be changed, thus a request to clear results is being made on TextField value changes

EDIT: Added TextFieldValue.isBlank() extension

What is savedInstanceState ?