Some themes or plugins use custom fields starting with an underscore (for example
_price) to store related information. These fields are not being listed in the Views GUI by default, as they are supposed to be hidden from end users.
To use a hidden custom field in your Views, go to the Toolset->Settings page and click the Front-end Content tab. Click Select custom fields button in the Hidden custom fields section. In the dialog box that opens, select the desired field from the list and click Apply.
The hidden custom field you selected will now be available to use in Views, just like any other custom field. You can use it for ordering, filtering or display it in the Loop Output section.
The following table shows some typical usage scenarios for hidden fields.
|Using hidden fields in loop output||Using hidden fields in query filters||Using hidden fields in ordering|