tie in

/T AY1 IH0 N/
verb
  1. 1

    To fit in or harmonize (with)

    โ€œthis paragraph does not tie in with the greater themes of the storyโ€

noun
  1. 1

    Something that is related or connected to another

  2. 2

    An authorized product based on a media property, such as a film or video game, by way of cross-promotion.

  3. 3

    An association or connection between things

Source: https://en.wiktionary.org/wiki/tie%20in, https://en.wiktionary.org/wiki/tie-in