Yes, you are able to link one issue to another.
In the example below, you can see that issues #13 and #14 start off as separate issues.
Next, on issue #13 we added the wording 'closes #14' to link the issues together.
Now, you can see that issue #13 is nested under #14
Because #13 is now connected to another issue, it will no longer appear as a standalone issue on the board.