Ultimate User allows you to create custom fields in the register page. I have added address and phone. Where do they go? You cannot edit or even find them in the back end user interface. I added them so that they could appear in the user directory listings and cannot find any way to edit that listing or find the fields.
I can confirm that the values are saved in the User meta table as I have been working on the same exact thing. meta_key contains the name of the input (case sensitive) and meta_value the actual value. User-ID is also a column, so, theoretically, you can get all the values for a certain user. I'm still working on this query so I can get the data for each user on a row. We are also using the paid plug-in WP Data Tables to display the data from Ultimate Member.
Follow this link, https://gist.github.com/magnific0/29c32c7dabc89ab9cae5, and it will show you how to adjust your functions.php file in your themes folder to show the custom UM metadata under the user menu.
works like a charm :)
Custom fields are recorded by Ultimate Member in the wp_usermeta table in this form:
So you can get the value of a custom field by using get_user_meta() function:
echo get_user_meta( $user_id, $field_id, true );