Hi

I am not clear about the usage of 'in that' vs 'because'.

I have read that 'in that' qualifies for the preceding sentence, whereas 'because' is used to show cause-effect relationship. And 'in that' gets a higher precedence over 'before' in GMAT, but still i am not very clear over their usage. So could you please help me out.

'in that' is EXPLANATORY and LIMITING. in other words, it explains the sense in which the immediately preceding description is used (explanatory), and it specifically implies no more than that sense (limiting).

example:
my approach differs from yours in that i am more aggressive.
--> explanatory: the difference in aggressiveness is the way in which our approaches differ
--> limiting: there are no other significant differences between our approaches

--

'because', as you say, shows a cause-effect relationship.

example:
my approach differs from yours because i am more aggressive.
--> there could be all sorts of differences between our approaches - some of which may have no direct connection to aggressiveness - but the ultimate source or cause of those differences is the difference in aggressiveness.

it's not that "in that" has a higher priority; it's that the confusion is a one-way street. i.e., most writers, and ALL speakers, of english commonly use "because" in situations where "in that" would be more appropriate, but it would be ridiculous to use "in that" in a situation demanding "because".
because of this imbalance, it's highly likely that a question whose answer choices feature both "because" and "in that" should take "in that"; if "because" were the correct choice, then "in that" would sound absurd.

the same pattern is evident with "like" vs. "such as". most writers (and essentially all speakers) regularly use "like" in place of "such as", but not the other way around. therefore, if any confusion between "like" and "such as" is possible, then "such as" is almost certainly the correct alternative.