Definition
Compounding is a concatenative process which involves the combination of two roots or stems together to form a new word.
In Halkomelem, compounding seems very rare or almost non-existent. (Suttles, 2004, p. 23)
In contrast, Secwepemctsín has instances of compounding, but they are almost always incorporative. (Gibson, 1973, p. 38) Therefore, the language does not really have clear examples of non-incorporative compounds in which the two roots/stems stay unchanged.
Examples

In Halkomelem, the word sx̌ə́x̌əłnet ‘Sunday, week’ is formed with the linking element -ł-, which may be interpreted as a redaction of -aʔł ‘attributive’, and nét ‘become night’. sx̌ə́x̌əłnet demonstrates a Western-influence on the conception of time and a contemporary origin and as a result may be identified as either a compound or as a new lexical suffix. (Suttles, 2004, p. 288)
References
Suttles, W. (2004). Musqueum reference grammar. UBC Press. SFU Student Access.