Is there a way to customize Content Assist in xtext?

Question

Suppose I have a grammar "A" which cross references from another grammar "B". for example:-

test.mydsl->

entity A{
    var p;
    var q;
}

otherTest.mydsl1

entity B{
        var "??"
    }

so right now what is happening is as i press Ctrl + Space in "??" of above code piece, it shows A.p and A.q in content assist but i dont want that i just want it to show "p" or "q" in content assist. Is there some example from which i can refer where content assist just shows options with simple name and not FQN ?