It's very different than what is already done. For example, suppose the group is descendants of John Doe plus spouses. Suppose John Doe's granddaughter Sarah Doe marries William Smith, so William is in the group. Suppose the left side bar is in Group mode and the main view is in Pedigree View. Suppose William Smith is not in the Pedigree View at all and suppose you click on William Smith in the group sidebar.
At this point, William Smith will be in the left most position of Pedigree View and the rest of Pedigree View will be completely empty (assuming William has no parents in the database). There is no indication anywhere on the screen that William is married to Sarah Doe nor how it is that William fits in with anybody else in the database. You can click the little red arrowhead just to the left of William to move him one position to the right. Sarah will now appear and it will be obvious that William is the husband of Sarah Doe and that Sarah is the granddaughter of John Doe. I'm simply asking for an option to move William one position to the right automatically under these circumstances so you can see on the screen how he fits into the family. In other words, the option would display both the newly highlighted person and their spouse.
I will certainly agree that clicking the red arrowhead to the left of William is not particular burdensome for any one particular person. Where it becomes burdensome is when you are scrolling up and down the group sidebar in the left panel. The same thing can happen in the index sidebar. I find myself constantly having to stop scrolling to click the red arrowhead.
What I'm suggesting should certainly not be the default mode of operation for the Pedigree View, but I think it would be very helpful for it to be a selectable mode of operation.