What is the rule for composing two words, when one of them is hyphenized or has spaces?
It is usually better to rephrase such constructions. However, if you cannot do this, you can use an en dash instead. Quoting from The Chicago Manual of Style:
The en dash is used in place of a hyphen in a compound adjective when one of its elements is an open compound or when two or more of its elements are open compounds or hyphenated compounds (e.g., a quasi-public–quasi-judicial body, the post–World War II years).
You can write the phrase in your question as
EFSMA-EE–time and EFSMA Telecom–time