How can we check which two fields among dimensions and/or amonst dimension and fact table(s) are joined if there is a link (line) between them.

For example in the Diagram Editor or even the Query Designer, we can get properties of a linking line and find out which two fields on both sides are linked (this is useful if there are many links between 2 sides and if one needs to be sure if thecorrect fields are linked).

Also, I just want to confirm that in the cube editor, it makes no
difference which direction I drag the 1st field from (i.e. which
dimension/fact) and where I drag it to. Is this correct?