disable button after a click

I want to achieve that after clicking a button in a hud the button is disabled until another button is clicked.
This click on a second button reactivates the first one.
I call the buttons inside the levelblueprint, not in the widget.
Thanks a lot.
Here is a screenshot:

Sheesh! Stop with Hud already, UMG is better for Common UI like buttons scroll bars and controlling their behaviour, and hud is better for things that require direct drawing like Radars and Crosshairs.

So shift the UI stuff like your button to UMG and it should be fairly straightforward from there for you to understand

You can disable a button using the Set Is Enabled node.
Also you should probably store your casted widget as a variable, but otherwise, drag off from the return value, get your button, then use that node after the bound click event