RE: How to filter a dataverse table on the basis of another dataverse table with list rows action in powerapps flows?
Hi rahul78610
You can Utilize the List rows action, and mention this fields :

In the Select columns field, you mention the shema name of columns that you want export.
And then, you will navigate to your Dynamics 365 and navigate the advanced search

You will search all employees and in the filter you add a related table (Tasks) and Guid (Tasks table) does not contain data.

Then you will click on Download Fetch XML query
You will add this Query in your Power automate action

Hope that's helpful for you