Idea Summary
Provide link attributes to the Tree region.
For example, in Link field type of Interactive Grid it is possible to set the following in order to open links into a new browser tab:
target="_blank"

Use Case
User wants tree links to open into a new browser tab or same tab conditionally.

Preferred Solution (Optional)
https://stackoverflow.com/questions/60962695/how-to-open-oracle-apex-tree-link-in-new-window-conditionally
Instead of using Link Column, adapt your SQL and set Link as a URL with the following:
javascript:window.open("&LINK.","&TARGET.")
where:

• “LINK” is the name of the field containing the URL
• "TARGET" is the name of the field containing the target type ("_blank", "_self", etc.)
  Limit: when LINK is null, it brings you to a blank page