While building a custom form in Planning, we encountered an unusual issue. We like to build forms with user variables and substitution variables to reduce future maintenance needs and make the forms more versatile. Normally, we select a variable from the available drop-down member selection. But we wanted to use a custom substitution variable and none of those were in the listing. Only out-of-box variables were available.

We have several custom variables set up.

Luckily, the solution is simple. Even though the custom substitution variables are not in the member selection listing, they can be manually typed into the dimension field on the form. Be sure to include the ampersand prefix.

The form saves without issue.

And the form opens using the value of the custom substitution variable.

This same issue was also found in valid intersections.

Again, we were able to type the custom variable into the dimension field.

There may be other areas in Planning where this deficiency in the member selection exists. I will be opening a SR with Oracle to determine if this is a known issue, a bug, or expected behavior. I’ll update this post when I get an answer.
As always, happy EPM’ng!
Update 11.17.2022: Oracle has confirmed this is a bug, development will be working to resolve.
Update 11.22.2022: Development is planning to fix in FY23 Q1( January, February or March).