Translation:It did not take much for them to get lost.
My view of the literal meaning;
non c'è volute molto = "It did not want/need much" = "not much was wanted/needed"
perché = "in order that'. If you consider the literal translation of perché to be "for that", i.e., per che, then it's not such a stretch.
si perdessero = "they lost themselves" = "they caused themselves to become lost/to be lost".
Putting it all together in a literal sense, "It did not want/need much for that they caused themselves to be lost."
A lot of reflexive verbs can make sense if you put them in terms of: "[I/you/he/she/we/they] caused [my/your/him/her/our/them]self/selves to be [past participle of verb]".
I strongly disagree. I didn’t understand this sentence at first. There were very interesting things to learn from it. The expression “ci vuole” I have seen before but this was the first time to see it in past tense. “Perché not only means “why” or “because” but also “in order that” or “for” when followed by the subjunctive. “Perdere” (to lose) becomes “perdersi” (to get lost). Excellent sentence to study.