The name is all-telling in this case:
"Services in this group" is a list of network services (DNS, AD, web, etc, etc) that is being accessed inside the group you've selected. In your case the group is everything in vlan-141.
"External Services Accessed" is a list of network services that the selected group (vlan-141) is accessing that are outside vlan-141. So if you have a DNS server outside vlan-141 and systems in vlan-141 are using it for lookups, that relationship will list there.
Hope that helps!
Because both services accessed the endpoints RT-XXXXX.
It is not really the same flows as I think the SRC IP for instance may be different.
I invite you to click on the flows to get more details about them .