I see this sign near one of the cafeterias at Nankai University.
èrlóu xīnyǔ cāntīng yóucǐ shànglóu
second floor Sinew cafeteria; herefrom go upstairs
Where 新宇 (xīnyǔ; Sinew) is the company name.
I'm interested in 由此上楼, and particularly how 由此 is being used. I guess it makes sense, effectively meaning "go upstairs here", although I would expect some combination of 这里 (zhèlǐ; here） and 上楼 (shànglóu; go upstairs) to work. The question Are there any online resources for learning Chinese 4-character idioms and its top answer makes me think it might be something special.
Question: How is 由此 used?
I'm seeking just the general idea about how 由此 is used, ideally with some other short examples. The linked question gives this example
from this, it can be seen that ... (dict.cn translation)
It seems to be quite different usage to 由此上楼, however.