This is a rare sound. Dahalo has both a palatal lateral fricative and an affricate; Hadza has a series of affricates. In Bura, it is the realization of palatalized /ɬʲ/ and contrasts with [ʎ].
The IPA has no dedicated symbol for this sound. The devoicing and raising diacritics may be used to transcribe it: ⟨ʎ̥˔⟩ (decimal ʎ̥˔). However, the "belt" on the existing symbol for a voiceless lateral fricative, ⟨ɬ⟩, forms the basis for other lateral fricatives used in the extIPA. The third one below, ⟨⟩, is the palatal lateral fricative: