Using OData Query to Filter SharePoint List Items by Lookup Fields in Microsoft FlowOn < 1 minute
Get items and
Get files SharePoint actions in Microsoft Flow help you get items from a list and a library respectively. These two actions have the same capabilities but with a little twist.
Get items action only works with lists while
Get files action only works with libraries. It is important to know this difference. These actions supports specifying filter queries so you can filter items on the server which has better performance than filtering an entire results in your flow.
Filtering on columns are very easy except for lookup columns to another list. You can filter by column name like City (a textfield) using:
City eq 'New York'
Filtering on a lookup column can be done using
FieldName/Title eq 'Lookup Value'
FieldName/Id eq 'Lookup Id'