How to set up multiple-choice queries, how to control the main grid initialization work?

I have several questions to ask you:
1) In the main object class grid search screen, when the object associated with the query, the search dialogue press the F2 key, it is possible to select a plurality of data query!
I want to ask how to achieve this demand?

Screenshot described as follows:

2) I was able to control the initialization of the main grid do?
For example: I need to ClassStructure different values, search, display different properties on the main grid (with field properties on the model, there are also virtual field properties)