Depending on your goals and desired features, you can choose the best WordPress plugin for your multi-level affiliate marketing business, or "liaison" program as you may call it. Based on your description, here are some possibilities to think about:
Leading candidates for multi-tier marketing:
Strong multi-level capabilities are provided by AffiliateWP, a well-known plugin that lets you specify commission structures up to three layers deep. It offers accurate referral tracking, smooth integration with WooCommerce and other platforms, and analytical reporting.
WordPress Affiliate Manager: WP Affiliate Manager is a good alternative that offers multi-level capabilities and dashboards that are easy to use for both you and your affiliates. It has tools for tracking coupons, compensation systems that may be customized, and comprehensive reporting.
The Ultimate Affiliate Pro plugin is a premium tool intended for intricate affiliate networks. With its adaptable commission structures, customisable awards for high performers, and sophisticated reporting with real-time insights, it shines in multi-level management.

Plugins for general affiliate marketing that are versatile:
SliceWP: Well-known for its adaptability, SliceWP enables you to design any kind of affiliate scheme, including hierarchical models. It includes features like tracking coupons, personalized registration forms, and automated payouts, and it interfaces with other platforms.
Post Affiliate Pro: With its powerful tracking, multi-level functionality, and ample customization possibilities, this premium solution serves huge affiliate networks. It works with numerous marketing platforms and is capable of handling intricate commission schemes.
Thinking about the framework of your "liaison" program:

Pretty Links: Use Pretty Links to effectively manage and disguise affiliate links. In order to maximize conversion rates, it may even rotate various affiliate links, track clicks, and automatically shorten and brand your links.
EasyAzon: If your main source of revenue is Amazon products, EasyAzon makes managing affiliate links and product display on your WordPress website easier. It offers tracking capabilities, automates link updates, and interfaces with Amazon's Product Advertising API.
Bonus suggestion:
ReferralCandy is a WooCommerce plugin that specializes in referral schemes that reward recommendations made by other users. It features social media sharing buttons, gamification components, and easily configurable referral benefits, all of which link with WooCommerce.
The ideal plugin ultimately depends on your unique requirements.
Here are a few more things to think about:
Budget: While there are free plugins available, the features and capabilities of paid solutions are frequently greater.
User base and traffic: Pick a plugin that can grow along with the expansion of your program.
Technical proficiency: Take into account how at ease you are installing and configuring plugins.
Verify the plugin's compatibility with the platforms and tools you already use.
Support: Select a plugin that offers dependable help in case you require it.
With this knowledge, hopefully you will be able to select the ideal WordPress plugin for your "liaison" program. Don't forget to do extensive research on each choice and take your unique needs into account before choosing one.