Mutablestateof - State hoisting

What to do to manage one state in two functions? (openDialog) How to transfer openDialog state from ProductDialog() to AppBar()? I know I can make a separate class per state but I don't want to.

@Composable
fun ProductDialog() {
    val openDialog = rememberSaveable() { mutableStateOf(true) }
    val productNameState = remember { mutableStateOf("") }

    AlertDialog(
        onDismissRequest = { openDialog.value = false },
        title = { Text(
            modifier = Modifier.padding(bottom = 8.dp),
            text = "Add new product",
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold
        ) },
        confirmButton = { Button(onClick = { openDialog.value = false }) {
            Text(text = "Add") }
        },
        dismissButton = { Button(onClick = { openDialog.value = false }) {
            Text(text = "Cancel")
            }
        },
        text = {
            Column() {
                TextField(value = productNameState.value, onValueChange = {
                })
                TextField(value = productNameState.value, onValueChange = {})
            }
        }
    )
}

@Composable
fun AppBar() {
    val openDialog = rememberSaveable() { mutableStateOf(false) }

    if (openDialog.value) ProductDialog()

    Scaffold(
        topBar = {
                TopAppBar(
                    actions = { Icon(imageVector = Icons.Default.Menu, contentDescription = null) },
                    title = { Text(text = "Shopping List Compose") })
                },
        floatingActionButton = {
            FloatingActionButton(modifier = Modifier.padding(10.dp), onClick = { openDialog.value = true }) {
            Icon(Icons.Default.Add, contentDescription = null)
        }}
    ) {
        ListItems()
    }
}

What to do to manage one state in two functions? (openDialog)

From the example you shared, it seems that the only use of openDialog in ProductDialog is to close the dialog. You can instead paas a lambda to ProductDialog to close the dialog.

@Composable
fun ProductDialog(closeDialog: () -> Unit) {
    AlertDialog(
        onDismissRequest = closeDialog,
        title = { ... },
        confirmButton = { 
            Button(onClick = closeDialog) {
                Text(text = "Add")
            }
        },
        dismissButton = { 
            Button(onClick = closeDialog) {
                Text(text = "Cancel")
            }
        },
        text = { ... }
    )
}

@Composable
fun AppBar() {
    val openDialog by rememberSaveable() { mutableStateOf(false) }

    if (openDialog) ProductDialog { openDialog = false}

   ...
}