Profile edit approval

Is it possible to add an approval step before the user updated fields are visible on profile ?
e.g. If a user update his/her address, it shouldn't be visible on profile. The update will be visible on profile only after a moderator 'approves' it.

Only image fields have approval. Other fields do not at this time. You'd have to try and put together something with CB Auto Actions. For example you'd have a checkbox field that's used to toggle if approved or not. You'd use CB Conditional to show/hide your file field based off the value of that checkbox field. You'd then toggle the checkbox field back to a value of 0 if the file field changed. Below should be able to pull this off, but it's a bit of work. You'll need CB Privacy to ensure the checkbox is moderator only edit.

File Field Name: cb_file
Checkbox Field Name: cb_fileapproved

Auto Action
Global
Triggers: onAfterUserUpdate
Action: Field
User: Automatic
Access: Everybody
Conditions
1: [var1_cb_file] Not Equal To [var3_cb_file]
Action
Field: cb_fileapproved
Operator: Set
Value: 0

File Field Condition
Display: Field conditional show
Field: cb_fileapproved
Operator: Equal To
Value: 1
Locations
Registration: No
Profile Edit: No
Profile View: Yes
Userlists Search: No
Userlists View: Yes

Checkbox Field Privacy
Edit Display: Moderators only edit display

Using this you basically can have approval for any field you want. It shouldn't display on profile until the checkbox field has been checked, which will reset back to unchecked if the field value changes. There is no notification behavior for this, but you could setup an email auto action using the same conditions as the field auto action if you want a notification.