To call Biography profile field code is $post[field1]

and to call Location profile field code is $post[field2]

i need member can call field2 variable, by putting this code : $post[field2]
inside they field1 form, for example put like this in field1 form :
My name is John, i am from $post[field2]

i already tried it, but this code : $post[field2], is still not changed to the field2 content, still showing like this in postbit : $post[field2]

I need this, because i have about 30 profile fields, and it is better if member no need to write same information again and again, and no need to update same information in another fields, just need to call the variables

please share if you have clue about this, GBU for all that trying to help