cast your net wider
cast (one's) net wider
To broaden one's search or criteria for something, thus giving oneself more options. A: "I don't know why John has only applied to Ivy League schools when he only has average grades." B: "I know, I've told him to cast his net wider."
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
cast your net wideror
cast the net wider
COMMON If you cast your net wider or cast the net wider, you include a larger number of people or things, especially when considering or choosing someone or something. The easiest way to find members is through friends of friends but if you want to cast the net wider, put an ad in your local bookshop. We will cast the net wider to look at other factors too. Note: You can also say that you cast your net wide, meaning that you include a large number of people or things. Clarke, as director of training, decided to cast the net wide in the search for the best candidates. England's selectors have been careful to cast their net wide to prepare for the World Cup. Note: The verb spread is sometimes used instead of cast. Ferguson advised him to spread the net wide in his search for players. Police had searched the local area and found nothing so they were spreading their net wider.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012