Reconstructions

PWS
*bi/ba - in; by means of (instrumental) (Arakelova 2001:31, Kogan 2015: 77)
An eventual derivation from either *bayt- ‘house’ or *bwˀ ‘to come’ is not to be excluded (cf. Voigt 1999:37, 39‒40, Blažek 2007:31).
In several languages (Ugr., Pho., Heb., Arm., Har., Gur.) this preposition has a meaning “from”, nearly opposite to the locative meaning “in”. These forms could be ascribed to a separate homonymous preposition which could be united with ESA forms of the type bn with the same meaning (Sab. bn, Min. bn, Qat. bn). However, it is essential that Akk. ina possesses both of these meanings (Arakelova 2001:33).
PWS
*baˁda - after, behind (Arakelova 2001:45, Kogan 2015: 78, 105)
Considered to be derived from the noun *baˁd- ‘distance’ (Tropper 2000:770, Gesenius 1910:297).
PWS
*badw- - wilderness, steppe, desert (EDA I 479)
PWS
*bdˀ - to lie (DRS 44; Kogan 2015: 550)
PWS
*bdd - to divide, to separate (EDA B 209)
PWS
*bḏr- - to scatter (?) (HALOT 118, Kogan 2015: 34)
Level?
PWS
*bhr - to be clear, to shine (EDA P 141–142)
A relation of Akk. bâru ‘to stay firm, stable, in good health, to become certain, proved, certified’ to *bhr is not to be ruled out.
PWS
*bḳṯ - to dig (out) (Kogan 2015: 287)
PWS
*bḳˁ - to split (HALOT 149)
PWS
*bāḳil(l)ā- - bean (EDA I 159)

Presumably connected with the root *bVḳl ‘a cultivated plant, shoot, seed, grain, cereal, vegetable’, but of uncertain ultimate origin.