You have opened the Filter dialog. Click [...] in the Value field.
In this dialog you select the comparison value that is to be compared to the selected property. You can use placeholders (such as "*" or "?"). Entry of several values within a cell (separated by semicolons) means an OR relationship.
Overview of the main dialog elements:
The list contains values comparable to the criteria. If, for example, you selected a structure identifier as the criterion, the selection dialog will contain the values of this structure identifier as they appear in the project.
See also