There is a way to do it but you need to pay attenction when use this method:
Blueprint A need to have a Branch that get Refresh Blueprint B set by default to false and if you click to enable it it become true so construction script continue fairing set variable and if you dont reset refresh condition your engine crash.
Next you need a variable to ref the blueprint B and from it set the variable inside the blueprint with new 1 from Blueprint A
In blueprint B you can do the same think take a variable from A and set it with 1 in B and viceversa you can take variable for your need by get it
Before place both blueprint save all becouse if you made a mistake in costruption script it generate infinit loop so your engine crash, before test it save all and place both bp in your scene
Now you need to set in BLueprint A the ref to blueprint B
Now set Blueprint B ref to Blueprint A
Now the comunicazion between construction scripts was set up and you can try to test it