Each dimensional table needs to include a primary key that corresponds to a foreign key in the fact table. As a rule, each foreign key of the fact table must have its counterpart in a dimension table.
This could be addressed by the use of composite keys. They're resultants of combining two or more columns in a table, which can be used to uniquely identify each row in a table. But do not guarantee uniqueness when taken individually.
In addition to the suggestion to combine multiple fields within a composite key you may also need some transformation to your fields, like converting strings to a number, combining date + time to a timestamp or to reverse the logic by splitting the parts, creating a date per makedate(year, month) or reverse and various other stuff - quite probably there are such possibilities.
