Q:

Render RJP.MultiUrlPicker package

How to change the RJP.MultiUrlPicker label Title on the umbraco backoffice code? 

And where do I find the multi url picker code on the umbraco to make any changes?

A:

The RJP.MultiUrlPicker package just uses the same dialog as the Umbraco Link Picker, which is used to insert links into rich text editors.
The view for this dialog can be found in the following location:

\umbraco\Views\common\dialogs\linkpicker.html

The label that you're looking to change (@content_nodeName) is actually being pulled from an XML language file, which you can modify by going to:

\umbraco\Config\Lang\en.xml

and changing the value of the key tag with alias nodeName.
If you do change the value of this property then you'll have to be careful when you upgrade your solution going forward, otherwise your changes may be overwritten.

