Variant form of 博

Yes; it is a historical written form of 博.

《集韻》, an 11th-century dictionary that groups characters by sound, records 𩫯; writing on Western Zhou bronze vessels shows older forms of 博. Taiwan’s Ministry of Education links 𩫯’s changed side to a walled settlement and 博’s use as a state name. The classical Chinese character dictionary 《說文解字》 explains 博 as 十 (“ten”) plus 尃 (“spread”); researchers of ancient Chinese writing instead see a shield and argue that 博 first wrote 搏 (“strike”), later borrowed for “broad.”