Teleport a player to their set spawn point (possible multiplayer compatability?)

I'm looking to create a item/block that sends the player to the Overworld when right clicked (whilst in a dimension that does ≠ the Overworld, of course). The only problem is that it sends you to the world spawn, which is impractical for survival. I want it to get it to work just like end portals; you always get sent to your set spawn point if you go through it.

It would also be great if this worked on multiplayer, and each player was sent to their own set spawn point (or world spawn if they do not have a set spawn point). If global variables are used, it will probably send all players to a single spawn point instead of their own (unless I'm not understanding how global variables work). If there isn't any way to make it multiplayer compatible, then perhaps someone could help me with a singleplayer method instead?

I've done research and am still at a dead end. I'm somewhat new to these procedures which may be why I'm so stuck, so no hard feelings if someone just tells me to do more procedure research myself.

EDIT: Apparently a "get spawn point coordinates procedure block" was added in 1.9.0, but after testing it, it only sends me to the world spawn point even after I set myself a new spawnpoint with a bed.