It is easy. Fire one 40 hours worker. Hire thirty-nine 1 hour workers. Congratulations! You've increased your "labor force" by 3800% !!!

You have a net loss of 1 man-hour however. I'm not totally sure how this relates to inflation, but jobs absolute numbers and gdp are only slightly related.

Another example would be to fire everyone making more than 100k$/year and relocate them to potato farming. In terms of gdp, this would be a net decrease despite the absolute worker count remaining the same

Everybody's aim in an economy is not to have to work, or at least to work less, and to produce more. No one wants to work more and produce less. So what we want is negative jobs (people working less) with positive GDP (people enjoying more goods and services.)

In bad times, when there is a loss of productivity or where people stop working in the productive (private) sector and go to work for the unproductive (public) sector, you absolutely can have negative real growth with more employment.