How to show data of user that flagged a content(2 flag types)?
Add a filter for the whole view that checks username in both fields as not null,  and set the operator to 'And'. 

In your view under 'Filter Criteria' do the following:


Add user name with the first relationship and set the operator to 'is not empty (NULL).
Do the same for the second username field.
Click the dropdown arrow next to add for 'Filter Criteria'. Select And/OR, Rearrange and add an 'AND' operator between the two filter. 
Hide the second username from display.


That way you can filter for users with both flags.