Deciding what values should be used in a data warehouse dimension?
If you have an attribute with the same granularity of the Fact table (i.e.: "TransactionID") and it is usually used to filter one single Fact table, you don't have to create a separate table (aka Shared Dimension) for it. Instead, this attribute can live in the fact table itself.
This is know as Degenerate Dimension

You can find more about it here: Degenerate Dimensions