In the "Extended Settings" of the Element Selection pallete, basically there are 2 cases:

My drawing has 5 Complex Chain.

case 1)

If I select in the drawing 3 complex Chain then it appears a black point in the "Complex Chain" element and the row is highlighted in blue.

case 2)

If I unselect all and I pick on the "Complex Chain" of the window, then appears a black point and the row is highlighted in blue.

The difference between case 1 and case 2 is that in the case 2, all elements (Complex Chain) are selected in the drawing whereas the case 1 maybe is just selected part of all complex chains of the drawing.

In my opinion, MicroStation should show a different symbol to differenciate both cases:

-a black point when the selected elements in the drawing are not all the elements of that element type. (in the example: 3 complex Chain selected of 5)

-a black square when all elements of that type are all selected in the drawing. (in the example: 5 of 5)