How can i filter Adapter Arraylist using Coroutines?

In my Fragment I'm using a Recycler View with multiple item types where i want to filter my parent array list based on some conditions and transfer its child list to child recycler view. I am able to filter parent recycler view on main thread but i am worried if the parent array list has thousands of data and performing filtration on main thread might be not good. So i want to filter my array list using coroutines. This is how i tried it using coroutines.

MainFragmentAdapter

 override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
  when (position) {
    1 -> {
            val goldAdapter = GoldAdapter()
             var filterGold = methodCallBack.filterData(gold,"gold")
             if (filterGold.isNotEmpty())
             goldAdapter.goldList = filterGold
             if (mRate.isNotEmpty())
             goldAdapter.goldRate = mRate[0].value!!
            holder.itemView.diamond_text.text = "Gold"
            holder.itemView.diamond_recycler.apply {
                setHasFixedSize(true)
                adapter = goldAdapter
            }
            holder.itemView.view_more_button.setOnClickListener {
                methodCallBack.click(gold)
            }
            goldAdapter.setListener(myContext)
        }

MainFragment

 override fun filterData(myList: MutableList<Item>,type : String) {
     mainFragmentViewModel.viewModelScope.launch {
        mainFragmentViewModel.myFilter(myList,type)
    }
}

MainFragmentViewModel

  private val filterGoldList = MutableLiveData<MutableList<Item>>()
  val _filterGold : LiveData<MutableList<Item>>
  get() = filterGoldList

    suspend fun myFilter(myList : MutableList<Item>,type : String) =
        withContext(Dispatchers.IO){
              myList.filter { it.isMainPageItem == true }
                    .let {
                          when(type){
                                "Gold" -> filterGoldList.postValue(it as MutableList<Item>)
                                "Silver" -> filterSilverList.postValue(it as MutableList<Item>)
                          }
                    }
        }

I am not able to return data back to adapter class.Is there any way to observe live data in adapter class?. Please help me to achieve it..