Here are two dictionary results for bottom line….

The final balance; the amount of money or profit left after everything has been tallied; The summary or result; the most important information; the upshot; the net-net
en.wiktionary.org/wiki/bottom_line

• the last line in an audit; the line that shows profit or loss
• the decisive point
wordnet.princeton.edu/perl/webwn

Double bottom line is a business term used in socially responsible enterprise and investment.
In practical terms, triple bottom line accounting means expanding the traditional reporting framework to take into account ecological and social performance in addition to financial performance
"People, planet and profit" succinctly describes the triple bottom lines and the goal of sustainability….wikipedia

Is there a false bottom line ??? ( in businesses)
A false bottom is an internal partition in a container, typically at the bottom of a drawer, suitcase or similar item, enabling the concealment of objects from a cursory examination of the item's contents….wikipedia…

Are you getting any ideas ? To join the two phrases….bottom line and false bottom ???

Bottoms Up to that !

Bottoms up is a drinking phrase….like cheers…..and has its origin from  the British Army  recruitments of hapless drunks…in the 18th /19th century

Bottom is….

Bottom is also a part of a human anatomy….often at the end of jokes and  ridicule…

 “An annoying person or any source of frustration may be termed "a pain in the ass"
“Terminating an employee may be described as "firing his ass".

And in the end…. ( the bottom line)

We have a bottomless pit that describes an abyss….but           Bottomless  also describes a costume in which the top half of the body is covered while the part below the waist is bare….. !!!!!