Sure. I'll do an explanation first, and try to get a screenshot or video up later.
If you set a motor output with a sync group of "0", it will update its output immediately. (This means the update does not wait for any sync group to take effect)
If you set a motor with a sync group of decimal 64 (binary 00100000), then it will wait for the 6th sync group to be updated. If you wired decimal 65 (binary 00100001) into the "update sync group" command, it would update both the 6th and the 1st sync group.
If you wanted to update ALL the sync groups, you would wire a value of 255 (decimal 11111111).
EDIT:
So, for your example, how complex should it be?
Do you want to see how to update a single sync group?
Do you want to put a delay between when you send the motor outputs, and when you send the sync group?
Do you want to update multiple sync groups at once?
Do you want to be able to update a single motor through either of two sync groups?
Do you want a video to walk you through this?