How to calculate Custom Field Changes time?

I just built something JUST like this! I think you need to do it in two steps. 

step 1:  Create a timestamp attribute for when the field changed. 

Step 2: create a new date_diff metric to compare the custom attribute to ticket created. 

we're going to do this guide here, basically, but instead of internal comment, it will be changes to that field. 

The first formula would be a standard attribute: 

Title: "Customer Profile - Timestamp"
IF ([Changes - Field name] ="Customer Profile" AND [Changes - New value] != "0" )
AND DATE_FIRST_FIX([Update - Timestamp],[Changes - Field name],Changes - New value],=[Update - Timestamp])
THEN
[update timestamp]
ENDIF

Then, you would need to make a top level metric to diff it against ticket created: 
DATE_DIFF([Customer Profile - Timestamp], [Ticket Created - Timestamp], "nb_of_hrs")

Then you'd need to customize how it displays; 

1. Edit the metric you just created, set it's default aggregator to AVG, display format to Custom, and set Decimal points to 1 and Suffix to hrs
   
   
   And that should get you an output of how long it took for that field to get a value, in hours, since ticket creation! 

@cj95, thank you for your insight
Is it possible to just use this part to catch any changes in that field?
IF([Changes - Field name]="Customer Profile" )