That is what mesh will do. Check this training video (Module 7) on how to set it up. In summary: disable the extended SSID option (or leave it disabled), configure the APs while connected to the same wired network to form a cluster, then disconnect one (mesh point) and power it within the range of the connected AP (mesh portal).
Mesh connection will run on the 5 GHz radio
Throughput/performance on the 5GHz will reduce (50-75% reduction from the maximum) as the mesh point needs all traffic for clients connected there to be repeated by the mesh point.