Hi there - i just send question about it to scriptcase - but maybe somone already had that problem before and solved it - if not i will inform comunity here if i will find solution to resolve that problem.
use scenario:
- User have to open grid app without using filter form before
- Grid apear and in dynamic search are turned on predefined fields - soo simply if user like to change data set he simply expand dynamic view change and save it to get result on grid.
What we have tested to this moment
We was trying to debug sc grid app looking for diferences in sql when you are using or not filter app in grid - there is no difference in result sql.
You can easy check filter sql where by sc_where_filter but in end sql sc_where_current its simply sumarized. Soo its not a place to turn on dynamic fields by modyfing where clause.
Soo simplify question :
How to load grid app with configured already dynamic search - with preselected fields in that dynamic search.
expected result looks same like grid started after you select first some data in advanced search - simply how to inform grid that he should show specyfied fields in dynamic search - show selected not in dropdown.
Sorry for describing that twice 
with different words - but i am not native speaker and i prefer to be sure that you guys understand me.
Still no answer from support in that case and coumunity i silent soo no one did already that research guys ?
Waiting for feedback
Radek