I'll walk you through for the threshold.
Third parties under the bill will only be able to use contributions from Canadians and permanent residents for regulated activities. They will need to report on those, of course. They will be able to use their own funds—those are funds not received from Canadians or permanent residents, for example, selling merchandise, their other business lines, etc.—if all those contributions do not exceed 10% of their overall revenues in the previous year, as you've noted.
If I meet that limit, if I'm a third party and I have, let's say, $1,000 in contributions and the overall funds that I have are $9,000 of my own revenue, for donations at 10% of my overall income, which was the $9,000, that $1,000 is 10%, so then I would be able to use my own funds because I meet that threshold.