That stuff is like 50% ester and 30% PAO (synthetic oil base). Normally that much ester would eat away all seals. Since it doesn't, it must be bio based.
The only easily available bio based ester I can think of is biodiesel (make sure its 98%+ actual biodiesel not some 20% biodiesel blend with aggressive marketing). Please don't construe this as me recommending you fill your crankcase with 50% biodiesel! You could put 1:128 biodiesel:gasoline in your fuel safely, but it would lower your octane rating slightly so might not be cost effective.
Lubegard Biotech is bio ester based - 3 ounces per quart in the crankcase.
www.lubegard.com
Auto-Rx has the cyclohex(anone,ane,ene) family in it and some ester but it is dosed in conservative quantities. The right way to do it IMO. Like BG 109 EPR and maybe others also have cyclohex*. Effective, sure, but a little old school in 2020. Heh, limonene (citrus oil cleaner) is a cyclohexene that could maybe be a cheap oil additive - and it smells good. PEA is considered the modern best practice (Gumout, CRC, Techron). B-12 Chemtool and Seafoam are very very old school petroleum and alcohol solvents. They do also work and are cheap (well Chemtool is, Seafoam is overpriced).
I still recommend putting these things in the fuel system. Like Gumout Multi-System. It's slower but a sure thing and zero chance of unintended damage/consequences.