Following airstrikes targeting terror group's financial network, army unveils secret money bunker, located underneath Al-Sahel Hospital in heart of Lebanese capital; 'Funds stored here could have been used to rebuild Lebanon, but instead, they are used to rebuild Hezbollah'
Based on their presented intelligence, the bunker is accessible from adjacent buildings, not the hospital itself. The bunker is said to be located beneath the hospital.
https://www.timesofisrael.com/liveblog_entry/lebanese-hospital-opens-doors-to-journalists-aiming-to-disprove-idf-claim-that-its-housing-hezbollah-cash-bunker/
Edit:
https://www.lbcgroup.tv/news/news-bulletin-reports/808268/lbci-enters-sahel-general-hospital-amid-israeli-allegations-of-hezboll/en