As I understand the term コンペ先 translates as a "competitor" (edit: from the examples in the answer, I think "contestant" seems more appropriate as there is an unspoken requirement for some contest or tender).
In a business situation in which there is company X asking for bids, and three companies: A, B, and C take part in a tender, which of the following is the proper use case:
- A calling B a コンペ先
- X calling A a コンペ先
Or are both correct?