I found the original source of your quotation and worked from there. The source is Hyun et al. (as you mention) and can be accessed through here. The words that appear in Hyun et al. are
To achieve organizational agility, companies must implement both high-speed and high-quality decision making (Ghasemaghaei et al., 2018; Westerman, 2009; Samsudin & Ismail, 2019).
I think that most people would shorten this simply by writing:
Hyun et al. (2020) addressed this by stating, “to achieve organizational agility, companies must implement both high-speed and high-quality decision-making” (p. 39)
... but if you really want to quote the extra referencing at the end of the sentence, then you should treat it according section 8.32 of the Publication Manual as mentioned on this APA page, and write:
Hyun et al. (2020) addressed this by stating, “to achieve organizational agility, companies must implement both high-speed and high-quality decision-making (Ghasemaghaei et al., 2018; Westerman, 2009; Samsudin & Ismail, 2019)” (p. 39)
Note that the quotation marks surround the entirety of the quoted material including the quoted in-line referencing, and that the page number on which the quoted material appears is situated at the end of the entire quote.
Do not include any of the following: Ghasemaghaei et al., 2018; Westerman, 2009; Samsudin & Ismail, 2019 in your own reference list, whether or not you include them in the block quote To do so would be to suggest that you had read them.
