How to create editable parameter based on conditions of another parameter?

[Gajanan Mahajan]

For Jenkins pipeline, I've a parameter say `Repository` and second parameter say `Branch`.

Based on `Repository` value, I want to auto-populate, value for `Branch`. 

Let's say - 

if `Repository` is `BobRepo` then for `Branch` value `BobBranch` is auto populated

if `Repository` is `AdamRepo` then for `Branch` value `AdamBranch` is auto populated

This can be achieved using `Active Choice Reactive Reference Parameter`.

But if user provides, some unknown value to `Repository` like `UnknownRepo` then he should be allowed to type in value in `Branch` parameter which is not possible with `Active Choice Reactive Reference Parameter`

Can you please help how to achieve editable parameter when conditions don't match?