Create 2 or more exposed filters for the same view
One way is that you can expose the fitler block by configuring (EXPOSED FORM option in views) the "Exposed form in block" to "Yes" for  as I have done below:



This way you will have the exposed filter available as a block at "/admin/structure/block".

Now as you want to create expose filter with 3 fields and 7 fields for the same view so than you do the following for that:


Create view of block type and add the required fields (if you want it to be of fields type).
Add the fields in "FILTER CRITERIA" section and this will be your expose filter fields. (Right now add the 3 fields).
Add another block for the same view, and now the view be same and you have all the fields available you have added in the previous block.
In the new block, add only new expose filter fields (just make sure you select "This page (Override)" while adding the fields for second block.


Hope this will work as you want.