It's the first way you describe it, Taika. To get the group pride for you, you'd have to be Brown Sitter, Brown Heart and Brown HoA at one point to qualify. same for the climbing the ladder - you'd need to serve as a staff member, *and* an admin, *and* an executive at one point to get it.
For...
I'll let Dralyn tackle Xylina's question, but Jeffan yes each position would count for its time so you'd have 2 years of staff service time for your example.