fenix/app/src/main/res/navigation/nav_graph.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nav_graph"
    app:startDestination="@id/homeFragment">

    <fragment
        android:id="@+id/homeFragment"
        android:name="org.mozilla.fenix.home.HomeFragment"
        android:label="fragment_home"
        tools:layout="@layout/fragment_home">
        <action
            android:id="@+id/action_homeFragment_to_searchFragment"
            app:destination="@id/searchFragment" />
        <action
            android:id="@+id/action_homeFragment_to_browserFragment"
            app:destination="@id/browserFragment" />
        <action
            android:id="@+id/action_homeFragment_to_settingsActivity"
            app:destination="@id/settingsActivity" />
    </fragment>

    <fragment
        android:id="@+id/searchFragment"
        android:name="org.mozilla.fenix.search.SearchFragment"
        android:label="fragment_search"
        tools:layout="@layout/fragment_search">
        <action
            android:id="@+id/action_searchFragment_to_browserFragment"
            app:destination="@id/browserFragment"
            app:popUpTo="@id/homeFragment" />
    </fragment>

    <fragment
        android:id="@+id/browserFragment"
        android:name="org.mozilla.fenix.browser.BrowserFragment"
        android:label="fragment_browser"
        tools:layout="@layout/fragment_browser">
        <action
                android:id="@+id/action_browserFragment_to_homeFragment"
                app:destination="@id/homeFragment" app:popUpToInclusive="true" app:popUpTo="@+id/homeFragment"/>
        <action
            android:id="@+id/action_browserFragment_to_searchFragment"
            app:destination="@id/searchFragment" />
        <action
            android:id="@+id/action_browserFragment_to_settingsActivity"
            app:destination="@id/settingsActivity" />
        <argument android:name="session_id" app:argType="string" app:nullable="true" android:defaultValue="null"/>
    </fragment>
    <activity
        android:id="@+id/settingsActivity"
        android:name="org.mozilla.fenix.settings.SettingsActivity"
        android:label="SettingsActivity" />
</navigation>