Your syntax isn't correct.
Mid("nara radh (Z8888)", 1, Find("(", "n radh (Z8888)") - 2)
would at least give us the proper syntax.
This returns a text of: nara r
Why does it return nara r?
Find("(", "n radh (Z8888)")
returns a position of 8 because the "(" is in the 8th position in the text.
When you add - 2, the 8 becomes 6.
Now your formula becomes
Mid("nara radh (Z8888)", 1, 6)
and returns nara r because you told it to start at 1 and return 6 characters.