You could create an FilterEntity with filter attributes, set a 1-* association to your TargetEntity. Create a DataSource microflow that creates a new FilterEntity, retrieves your list of TargetEntity based on the FilterEntity attributes, and in a Change Object activity sets the list. On the UI side you would need to create a DataView with the DS microlfow as a source, place inputs for the filters and a DataGrid2 with Association as a data source inside the DataView.
This way you can pass the FilterEntity with all the matches accessible through association to a microflow.
Note that DataGrids with association datasource might lose some built-in functionality that you would possibly need to create using custom microflows.
Hope this helps!