The sentence you provided is: "فالإخفاق في محاولة محلها البحث والتجريب ليس النهاية" (Failure in an attempt whose place is research and experimentation is not the end).
Let's break down the parsing of "محلها" (mahalluha):
محل (mahall): This is a noun meaning "place" or "position."
ها (-ha): This is a attached pronoun (ضمير متصل - damir muttasil) meaning "its" or "her." It refers back to "محاولة" (muhawala - attempt).
In this specific phrase, "محلها" (mahalluha) functions as the subject (مبتدأ - mubtada') of a nominal sentence that acts as an adjective (صفة - sifah) for "محاولة" (muhawala).
Here's a more detailed breakdown:
The phrase "محلها البحث والتجريب" (its place is research and experimentation) is a nominal sentence (جملة اسمية - jumla ismiyya) composed of:
محلها (mahalluha): This is the subject (مبتدأ - mubtada') of this embedded nominal sentence. It is مرفوع (marfu' - nominative) by default, and the "ها" is in the position of a genitive case (في محل جر مضاف إليه - fi mahall jarr mudaf ilayh) because it's a possessive pronoun attached to a noun.
البحث (al-bahth): This is the predicate (خبر - khabar) of the embedded nominal sentence. It is also مرفوع (marfu' - nominative).
و (wa): Conjunction (حرف عطف - harf 'atf).
التجريب (at-tajreeb): This is conjoined with "البحث" and is also مرفوع (marfu' - nominative).
The entire nominal sentence "محلها البحث والتجريب" (its place is research and experimentation) functions as a descriptive phrase (صفة - sifah) for the preceding indefinite noun "محاولة" (muhawala - attempt). In Arabic grammar, a nominal sentence can describe an indefinite noun, and in this case, it clarifies what kind of attempt it is: an attempt whose place/focus is research and experimentation.