It looks like TVDb has Gruen Transfer and Gruen under the same page, so there are no separate TVDb IDs for the two.

@rfl0216 said:

It looks like TVDb has Gruen Transfer and Gruen under the same page, so there are no separate TVDb IDs for the two.

I actually think these are the same same show, and it's just a name change. According to the ABC webpage for Gruen it's just finished 15th season:

The algorithm recommends Australia's favourite and only show about advertising - Gruen. Back for its 15th season, Wil Anderson and a panel of advertising know-it-alls are here to stop you from buying under the influence.

Similarly, the production website specifically says it's the same show.

Australia’s longest running, most beloved and only show about advertising.

Same show, all new ads. Host Wil Anderson is joined by a cracking team of experts including Russel Howcroft, Todd Sampson, Dee Madigan, Karen Ferry, Christina Aventi and many more favourites.

The team will decode and expose all the messaging we fall for, skip through and report for inappropriate content. From fashion moving faster than a speeding bullet, to Big Oil going green to get your green. The Gruen team will pull apart all the tricks used to get your clicks.

Gruen, the multi award winning (and losing, because truth in advertising matters) is back to enjoy another season of broadcast television before inevitably being reduced to a 7 second sponsored #ad on TikTok.

I'd probably recommend merging these shows on TMDB to align with that. The sub-series (Gruen Nation, Gruen Sweat) are probably just special episodes (they run in place of the regular episodes), rather than a spin-off.