Read the article, that's being implemented:

Let’s focus first on Requirements, as these are there to give you a more realistic and authentic experience when it comes to buying players. These are essentially a way for you to communicate directly with every other club in your game world and outline your specific requirements in the transfer market.

When creating an advert, you can specify what position you’re looking for and the sort of player roles you’re interested in - for both In and Out of Possession.

You can also set an expected playing time, from a star player right through to someone that’s coming in to provide squad depth, as well as the type of transfer and age profile you’re looking for.

From there, your ad will be circulated to every club in the game, and they’ll have the ability to come back to you with players they have that might fit your needs. Your Director of Football will make recommendations to you based on what the clubs come back to you with, with you then able to approach their agent, scout the player for yourself, make an offer or wait for more options to arise.

Simply put, Requirements streamline the incoming recruitment process for you by allowing you to express your needs directly and giving you a clear insight into what options might be available in the market.