Admin Grid filter for Custom table Magento 2

I have created a table with columns like patient_first_name, patient_last_name etc, I am able to get them in an Admin Grid Column.

<column name="patient_first_name" class="VendorModuleUiComponentListingColumnPatientName">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="editor" xsi:type="array">
                        <item name="editorType" xsi:type="string">text</item>
                        <item name="validation" xsi:type="array">
                            <item name="required-entry" xsi:type="boolean">true</item>
                        </item>
                    </item>
                    <item name="label" xsi:type="string" translate="true">Patient Name</item>
                </item>
            </argument>
        </column>

Inside the class, I concat first name and last name to display them in a single column in the admin grid using.

public function prepareDataSource(array $dataSource)
    {
        if(isset($dataSource['data']['items'])) {
            foreach($dataSource['data']['items'] as &$items) {
                $items['patient_first_name'] = $items['patient_first_name']." ".$items['patient_last_name'];
            }
        }
        return $dataSource;
    }

So this does its job to display the first name and last name together in the grid column, but when I use any filter to say, John Doe it searches only the patient_first_name column, which is correct since it is mapped that particular column but since the values would be stored as John in patient_first_name column and Doe in patient_last_name column, it will not return any result.

I used this solution to join both first and last names and show them together.
How can I merge columns in UI grid in Magento 2
The issue comes that when you add a filter Magento tries to look for a particular column in Db, so I can’t use something like patient_name and was getting the same error as here Magento 2 – custom admin grid field – error when sorting or filtering

I have tried _renderFiltersBefore but the issue with select remains.

I want to know a way how I can override the filter and write my own method which gives a select searching both first name and last name.